Sought after as a pet in the US and Europe, there are less than 1,000 left on Roti in eastern Indonesia.

Chester Zoo is home to four of the turtles - all aged three - which are affectionately dubbed "snurtles".

This species of turtle - so called because of their long necks - was discovered just 12 years ago.

Conservation projects

Kevin Buley, Chester Zoo's Curator of Lower Vertebrates and Invertebrates, said: "This species is being driven to the brink of extinction, sought after almost exclusively as an exotic pet species with collectors prepared to pay up to a £1,000 a time.

"The four we have here at Chester are an insurance population and, when old enough, will be part of a co-ordinated European breeding programme.

"Species like this will remain in what are essentially turtle arks until there is sufficient protection for their counterparts in the wild."

Through the Europe-wide Shellshock fundraising campaign, set up to support new and existing turtle and tortoise conservation programmes, Chester Zoo is also supporting conservation projects on Roti Island.